For pictures, descriptions, values, etc of American coins, there are 2 books -- "Guide Book of United States Coins-The Official Red Book
" and "Handbook of United States Coins-The Official Blue Book" -- and both are published annually by Whitman. The Red Book
has more and better pictures and descriptions, and the blue book has more realistic values. Between the 2 of them, they'll give you a good handle on the whole "what to look for" thing as well as answers to a lot of other questions. Those 2 books took me from "hopelessly ignorant, clueless newbie" status to "semi-ignorant newbie with 2 good books and he can now look up answers to most of his own questions" status. I'm still pretty green, but the books are a great help.
For Canadian coins, I honestly don't know, but I'd guess there must be Canadian counterparts of the 2 books mentioned above. Ask your local coin shop people.
Happy reading and happy hunting!